The research described in this proposal begins with completion and formal evaluation of MIDAS "a computer program designed to automatically construct decision models from an underlying medical knowledge base". The capabilities of MIDAS will be extended to knowledge-based construction of Markov decision models. A second project will develop a comprehensive knowledge management scheme for the problem of pulmonary disease in AIDS. This scheme will use a knowledge base structured according to knowledge needed to perform a decision analysis. It will incorporate summaries of relevant data, sources and quality of data and links to the original sources. This knowledge management scheme will be deployed in the hospital and evaluated in a group of medical residents at Robert Wood Johnson University Hospital.